Oro-nasal patient interface

ABSTRACT

A patient interface includes a frame including a textile material and a seal-forming structure provided to the frame. The seal-forming structure includes a foam material and/or a foam and textile material configured and arranged to form a seal with the patient&#39;s nose and/or mouth.

1 CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/067,688, filed Jul. 2, 2018, which is the U.S. national phase ofInternational Application No. PCT/AU2017/050024 filed Jan. 13, 2017,which designated the U.S. and claims the benefit of U.S. ProvisionalApplication No. 62/278,704, filed Jan. 14, 2016, each of which areincorporated herein by reference in their entirety.

2 BACKGROUND OF THE TECHNOLOGY

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in Patent Office patent files orrecords, but otherwise reserves all copyright rights whatsoever.

2.1 Field of the Technology

The present technology relates to one or more of the detection,diagnosis, treatment, prevention and amelioration of respiratory-relateddisorders. The present technology also relates to medical devices orapparatus, and their use.

2.2 Description of the Related Art 2.2.1 Human Respiratory System andits Disorders

The respiratory system of the body facilitates gas exchange. The noseand mouth form the entrance to the airways of a patient.

The airways include a series of branching tubes, which become narrower,shorter and more numerous as they penetrate deeper into the lung. Theprime function of the lung is gas exchange, allowing oxygen to move fromthe air into the venous blood and carbon dioxide to move out. Thetrachea divides into right and left main bronchi, which further divideeventually into terminal bronchioles. The bronchi make up the conductingairways, and do not take part in gas exchange. Further divisions of theairways lead to the respiratory bronchioles, and eventually to thealveoli. The alveolated region of the lung is where the gas exchangetakes place, and is referred to as the respiratory zone. See“Respiratory Physiology”, by John B. West, Lippincott Williams &Wilkins, 9th edition published 2011.

A range of respiratory disorders exist. Certain disorders may becharacterised by particular events, e.g. apneas, hypopneas, andhyperpneas.

Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing(SDB), is characterized by events including occlusion or obstruction ofthe upper air passage during sleep. It results from a combination of anabnormally small upper airway and the normal loss of muscle tone in theregion of the tongue, soft palate and posterior oropharyngeal wallduring sleep. The condition causes the affected patient to stopbreathing for periods typically of 30 to 120 seconds in duration,sometimes 200 to 300 times per night. It often causes excessive daytimesomnolence, and it may cause cardiovascular disease and brain damage.The syndrome is a common disorder, particularly in middle agedoverweight males, although a person affected may have no awareness ofthe problem. See U.S. Pat. No. 4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is another form of sleep disorderedbreathing. CSR is a disorder of a patient's respiratory controller inwhich there are rhythmic alternating periods of waxing and waningventilation known as CSR cycles. CSR is characterised by repetitivede-oxygenation and re-oxygenation of the arterial blood. It is possiblethat CSR is harmful because of the repetitive hypoxia. In some patientsCSR is associated with repetitive arousal from sleep, which causessevere sleep disruption, increased sympathetic activity, and increasedafterload. See U.S. Pat. No. 6,532,959 (Berthon-Jones).

Respiratory failure is an umbrella term for respiratory disorders inwhich the lungs are unable to inspire sufficient oxygen or exhalesufficient CO₂ to meet the patient's needs. Respiratory failure mayencompass some or all of the following disorders.

A patient with respiratory insufficiency (a form of respiratory failure)may experience abnormal shortness of breath on exercise.

Obesity Hyperventilation Syndrome (OHS) is defined as the combination ofsevere obesity and awake chronic hypercapnia, in the absence of otherknown causes for hypoventilation. Symptoms include dyspnea, morningheadache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a groupof lower airway diseases that have certain characteristics in common.These include increased resistance to air movement, extended expiratoryphase of respiration, and loss of the normal elasticity of the lung.Examples of COPD are emphysema and chronic bronchitis. COPD is caused bychronic tobacco smoking (primary risk factor), occupational exposures,air pollution and genetic factors. Symptoms include: dyspnea onexertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) is a broad term that encompasses manydiseases and ailments that impair the functioning of the muscles eitherdirectly via intrinsic muscle pathology, or indirectly via nervepathology. Some NMD patients are characterised by progressive muscularimpairment leading to loss of ambulation, being wheelchair-bound,swallowing difficulties, respiratory muscle weakness and, eventually,death from respiratory failure. Neuromuscular disorders can be dividedinto rapidly progressive and slowly progressive: (i) Rapidly progressivedisorders: Characterised by muscle impairment that worsens over monthsand results in death within a few years (e.g. Amyotrophic lateralsclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers);(ii) Variable or slowly progressive disorders: Characterised by muscleimpairment that worsens over years and only mildly reduces lifeexpectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic musculardystrophy). Symptoms of respiratory failure in NMD include: increasinggeneralised weakness, dysphagia, dyspnea on exertion and at rest,fatigue, sleepiness, morning headache, and difficulties withconcentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result ininefficient coupling between the respiratory muscles and the thoraciccage. The disorders are usually characterised by a restrictive defectand share the potential of long term hypercapnic respiratory failure.Scoliosis and/or kyphoscoliosis may cause severe respiratory failure.Symptoms of respiratory failure include: dyspnea on exertion, peripheraloedema, orthopnea, repeated chest infections, morning headaches,fatigue, poor sleep quality and loss of appetite.

A range of therapies have been used to treat or ameliorate suchconditions. Furthermore, otherwise healthy individuals may takeadvantage of such therapies to prevent respiratory disorders fromarising. However, these have a number of shortcomings.

2.2.2 Therapy

Continuous Positive Airway Pressure (CPAP) therapy has been used totreat Obstructive Sleep Apnea (OSA). The mechanism of action is thatcontinuous positive airway pressure acts as a pneumatic splint and mayprevent upper airway occlusion, such as by pushing the soft palate andtongue forward and away from the posterior oropharyngeal wall. Treatmentof OSA by CPAP therapy may be voluntary, and hence patients may electnot to comply with therapy if they find devices used to provide suchtherapy one or more of: uncomfortable, difficult to use, expensive andaesthetically unappealing.

Non-invasive ventilation (NIV) provides ventilatory support to a patientthrough the upper airways to assist the patient breathing and/ormaintain adequate oxygen levels in the body by doing some or all of thework of breathing. The ventilatory support is provided via anon-invasive patient interface. NIV has been used to treat CSR andrespiratory failure, in forms such as OHS, COPD, NMD and Chest Walldisorders. In some forms, the comfort and effectiveness of thesetherapies may be improved.

Invasive ventilation (IV) provides ventilatory support to patients thatare no longer able to effectively breathe themselves and may be providedusing a tracheostomy tube. In some forms, the comfort and effectivenessof these therapies may be improved.

2.2.3 Treatment Systems

These therapies may be provided by a treatment system or device. Suchsystems and devices may also be used to diagnose a condition withouttreating it.

A treatment system may comprise a Respiratory Pressure Therapy Device(RPT device), an air circuit, a humidifier, a patient interface, anddata management.

Another form of treatment system is a mandibular repositioning device.

2.2.3.1 Patient Interface

A patient interface may be used to interface respiratory equipment toits wearer, for example by providing a flow of air to an entrance to theairways. The flow of air may be provided via a mask to the nose and/ormouth, a tube to the mouth or a tracheostomy tube to the trachea of apatient. Depending upon the therapy to be applied, the patient interfacemay form a seal, e.g., with a region of the patient's face, tofacilitate the delivery of gas at a pressure at sufficient variance withambient pressure to effect therapy, e.g., at a positive pressure ofabout 10 cmH₂O relative to ambient pressure. For other forms of therapy,such as the delivery of oxygen, the patient interface may not include aseal sufficient to facilitate delivery to the airways of a supply of gasat a positive pressure of about 10 cmH₂O.

Certain other mask systems may be functionally unsuitable for thepresent field. For example, purely ornamental masks may be unable tomaintain a suitable pressure. Mask systems used for underwater swimmingor diving may be configured to guard against ingress of water from anexternal higher pressure, but not to maintain air internally at a higherpressure than ambient.

Certain masks may be clinically unfavourable for the present technologye.g. if they block airflow via the nose and only allow it via the mouth.

Certain masks may be uncomfortable or impractical for the presenttechnology if they require a patient to insert a portion of a maskstructure in their mouth to create and maintain a seal via their lips.

Certain masks may be impractical for use while sleeping, e.g. forsleeping while lying on one's side in bed with a head on a pillow.

The design of a patient interface presents a number of challenges. Theface has a complex three-dimensional shape. The size and shape of nosesand heads varies considerably between individuals. Since the headincludes bone, cartilage and soft tissue, different regions of the facerespond differently to mechanical forces. The jaw or mandible may moverelative to other bones of the skull. The whole head may move during thecourse of a period of respiratory therapy.

As a consequence of these challenges, some masks suffer from being oneor more of obtrusive, aesthetically undesirable, costly, poorly fitting,difficult to use, and uncomfortable especially when worn for longperiods of time or when a patient is unfamiliar with a system. Wronglysized masks can give rise to reduced compliance, reduced comfort andpoorer patient outcomes. Masks designed solely for aviators, masksdesigned as part of personal protection equipment (e.g. filter masks),SCUBA masks, or for the administration of anaesthetics may be tolerablefor their original application, but nevertheless such masks may beundesirably uncomfortable to be worn for extended periods of time, e.g.,several hours. This discomfort may lead to a reduction in patientcompliance with therapy. This is even more so if the mask is to be wornduring sleep.

CPAP therapy is highly effective to treat certain respiratory disorders,provided patients comply with therapy. If a mask is uncomfortable, ordifficult to use a patient may not comply with therapy. Since it isoften recommended that a patient regularly wash their mask, if a mask isdifficult to clean (e.g., difficult to assemble or disassemble),patients may not clean their mask and this may impact on patientcompliance.

While a mask for other applications (e.g. aviators) may not be suitablefor use in treating sleep disordered breathing, a mask designed for usein treating sleep disordered breathing may be suitable for otherapplications.

For these reasons, patient interfaces for delivery of CPAP during sleepform a distinct field.

2.2.3.1.1 Seal-Forming Portion

Patient interfaces may include a seal-forming portion. Since it is indirect contact with the patient's face, the shape and configuration ofthe seal-forming portion can have a direct impact the effectiveness andcomfort of the patient interface.

A patient interface may be partly characterised according to the designintent of where the seal-forming portion is to engage with the face inuse. In one form of patient interface, a seal-forming portion maycomprise two sub-portions to engage with respective left and rightnares. In one form of patient interface, a seal-forming portion maycomprise a single element that surrounds both nares in use. Such singleelement may be designed to for example overlay an upper lip region and anasal bridge region of a face. In one form of patient interface aseal-forming portion may comprise an element that surrounds a mouthregion in use, e.g. by forming a seal on a lower lip region of a face.In one form of patient interface, a seal-forming portion may comprise asingle element that surrounds both nares and a mouth region in use.These different types of patient interfaces may be known by a variety ofnames by their manufacturer including nasal masks, full-face masks,nasal pillows, nasal puffs and oro-nasal masks.

A seal-forming portion that may be effective in one region of apatient's face may be inappropriate in another region, e.g. because ofthe different shape, structure, variability and sensitivity regions ofthe patient's face. For example, a seal on swimming goggles thatoverlays a patient's forehead may not be appropriate to use on apatient's nose.

Certain seal-forming portions may be designed for mass manufacture suchthat one design fit and be comfortable and effective for a wide range ofdifferent face shapes and sizes. To the extent to which there is amismatch between the shape of the patient's face, and the seal-formingportion of the mass-manufactured patient interface, one or both mustadapt in order for a seal to form.

One type of seal-forming portion extends around the periphery of thepatient interface, and is intended to seal against the patient's facewhen force is applied to the patient interface with the seal-formingportion in confronting engagement with the patient's face. Theseal-forming portion may include an air or fluid filled cushion, or amoulded or formed surface of a resilient seal element made of anelastomer such as a rubber. With this type of seal-forming portion, ifthe fit is not adequate, there will be gaps between the seal-formingportion and the face, and additional force will be required to force thepatient interface against the face in order to achieve a seal.

Another type of seal-forming portion incorporates a flap seal of thinmaterial positioned about the periphery of the mask so as to provide aself-sealing action against the face of the patient when positivepressure is applied within the mask. Like the previous style of sealforming portion, if the match between the face and the mask is not good,additional force may be required to achieve a seal, or the mask mayleak. Furthermore, if the shape of the seal-forming portion does notmatch that of the patient, it may crease or buckle in use, giving riseto leaks.

Another type of seal-forming portion may comprise a friction-fitelement, e.g. for insertion into a naris, however some patients findthese uncomfortable.

Another form of seal-forming portion may use adhesive to achieve a seal.Some patients may find it inconvenient to constantly apply and remove anadhesive to their face.

A range of patient interface seal-forming portion technologies aredisclosed in the following patent applications, assigned to ResMedLimited: WO 1998/004,310; WO 2006/074,513; WO 2010/135,785.

One form of nasal pillow is found in the Adam Circuit manufactured byPuritan Bennett. Another nasal pillow, or nasal puff is the subject ofU.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan-BennettCorporation.

ResMed Limited has manufactured the following products that incorporatenasal pillows: SWIFT™ nasal pillows mask, SWIFT™ II nasal pillows mask,SWIFT™ LT nasal pillows mask, SWIFT™ FX nasal pillows mask and MIRAGELIBERTY™ full-face mask. The following patent applications, assigned toResMed Limited, describe examples of nasal pillows masks: InternationalPatent Application WO2004/073,778 (describing amongst other thingsaspects of the ResMed Limited SWIFT™ nasal pillows), US PatentApplication 2009/0044808 (describing amongst other things aspects of theResMed Limited SWIFT™ LT nasal pillows); International PatentApplications WO 2005/063,328 and WO 2006/130,903 (describing amongstother things aspects of the ResMed Limited MIRAGE LIBERTY™ full-facemask); International Patent Application WO 2009/052,560 (describingamongst other things aspects of the ResMed Limited SWIFT™ FX nasalpillows).

2.2.3.1.2 Positioning and Stabilising

A seal-forming portion of a patient interface used for positive airpressure therapy is subject to the corresponding force of the airpressure to disrupt a seal. Thus a variety of techniques have been usedto position the seal-forming portion, and to maintain it in sealingrelation with the appropriate portion of the face.

One technique is the use of adhesives. See for example US PatentApplication Publication No. US 2010/0000534. However, the use ofadhesives may be uncomfortable for some.

Another technique is the use of one or more straps and/or stabilisingharnesses. Many such harnesses suffer from being one or more ofill-fitting, bulky, uncomfortable and awkward to use.

2.2.3.2 Respiratory Pressure Therapy (RPT) Device

Air pressure generators are known in a range of applications, e.g.industrial-scale ventilation systems. However, air pressure generatorsfor medical applications have particular requirements not fulfilled bymore generalised air pressure generators, such as the reliability, sizeand weight requirements of medical devices. In addition, even devicesdesigned for medical treatment may suffer from shortcomings, pertainingto one or more of: comfort, noise, ease of use, efficacy, size, weight,manufacturability, cost, and reliability.

An example of the special requirements of certain RPT devices isacoustic noise.

Table of noise output levels of prior RPT devices (one specimen only,measured using test method specified in ISO 3744 in CPAP mode at 10cmH₂O). A-weighted sound pressure Year RPT Device name level dB(A)(approx.) C-Series Tango ™ 31.9 2007 C-Series Tango ™ with 33.1 2007Humidifier S8 Escape ™ II 30.5 2005 S8 Escape ™ II with 31.1 2005 H4i ™Humidifier S9 AutoSet ™ 26.5 2010 S9 AutoSet ™ with 28.6 2010 H5iHumidifier

One known RPT device used for treating sleep disordered breathing is theS9 Sleep Therapy System, manufactured by ResMed Limited. Another exampleof an RPT device is a ventilator. Ventilators such as the ResMedStellar™ Series of Adult and Paediatric Ventilators may provide supportfor invasive and non-invasive non-dependent ventilation for a range ofpatients for treating a number of conditions such as but not limited toNMD, OHS and COPD.

The ResMed Elisée™ 150 ventilator and ResMed VS III™ ventilator mayprovide support for invasive and non-invasive dependent ventilationsuitable for adult or paediatric patients for treating a number ofconditions. These ventilators provide volumetric and barometricventilation modes with a single or double limb circuit. RPT devicestypically comprise a pressure generator, such as a motor-driven bloweror a compressed gas reservoir, and are configured to supply a flow ofair to the airway of a patient. In some cases, the flow of air may besupplied to the airway of the patient at positive pressure. The outletof the RPT device is connected via an air circuit to a patient interfacesuch as those described above.

The designer of a device may be presented with an infinite number ofchoices to make. Design criteria often conflict, meaning that certaindesign choices are far from routine or inevitable. Furthermore, thecomfort and efficacy of certain aspects may be highly sensitive tosmall, subtle changes in one or more parameters.

2.2.3.3 Humidifier

Delivery of a flow of air without humidification may cause drying ofairways. The use of a humidifier with an RPT device and the patientinterface produces humidified gas that minimizes drying of the nasalmucosa and increases patient airway comfort. In addition in coolerclimates, warm air applied generally to the face area in and about thepatient interface is more comfortable than cold air. A range ofartificial humidification devices and systems are known, however theymay not fulfil the specialised requirements of a medical humidifier.

Medical humidifiers are used to increase humidity and/or temperature ofthe flow of air in relation to ambient air when required, typicallywhere the patient may be asleep or resting (e.g. at a hospital). Amedical humidifier for bedside placement may be small. A medicalhumidifier may be configured to only humidify and/or heat the flow ofair delivered to the patient without humidifying and/or heating thepatient's surroundings. Room-based systems (e.g. a sauna, an airconditioner, or an evaporative cooler), for example, may also humidifyair that is breathed in by the patient, however those systems would alsohumidify and/or heat the entire room, which may cause discomfort to theoccupants. Furthermore medical humidifiers may have more stringentsafety constraints than industrial humidifiers

While a number of medical humidifiers are known, they can suffer fromone or more shortcomings. Some medical humidifiers may provideinadequate humidification, some are difficult or inconvenient to use bypatients.

2.2.3.4 Data Management

There may be clinical reasons to obtain data to determine whether thepatient prescribed with respiratory therapy has been “compliant”, e.g.that the patient has used their RPT device according to certain a“compliance rule”. One example of a compliance rule for CPAP therapy isthat a patient, in order to be deemed compliant, is required to use theRPT device for at least four hours a night for at least 21 of 30consecutive days. In order to determine a patient's compliance, aprovider of the RPT device, such as a health care provider, may manuallyobtain data describing the patient's therapy using the RPT device,calculate the usage over a predetermined time period, and compare withthe compliance rule. Once the health care provider has determined thatthe patient has used their RPT device according to the compliance rule,the health care provider may notify a third party that the patient iscompliant.

There may be other aspects of a patient's therapy that would benefitfrom communication of therapy data to a third party or external system.

Existing processes to communicate and manage such data can be one ormore of costly, time-consuming, and error-prone.

2.2.3.5 Mandibular Repositioning

A mandibular repositioning device (MRD) or mandibular advancement device(MAD) is one of the treatment options for sleep apnea and snoring. It isan adjustable oral appliance available from a dentist or other supplierthat holds the lower jaw (mandible) in a forward position during sleep.The MRD is a removable device that a patient inserts into their mouthprior to going to sleep and removes following sleep. Thus, the MRD isnot designed to be worn all of the time. The MRD may be custom made orproduced in a standard form and includes a bite impression portiondesigned to allow fitting to a patient's teeth. This mechanicalprotrusion of the lower jaw expands the space behind the tongue, putstension on the pharyngeal walls to reduce collapse of the airway anddiminishes palate vibration.

In certain examples a mandibular advancement device may comprise anupper splint that is intended to engage with or fit over teeth on theupper jaw or maxilla and a lower splint that is intended to engage withor fit over teeth on the upper jaw or mandible. The upper and lowersplints are connected together laterally via a pair of connecting rods.The pair of connecting rods are fixed symmetrically on the upper splintand on the lower splint.

In such a design the length of the connecting rods is selected such thatwhen the MRD is placed in a patient's mouth the mandible is held in anadvanced position. The length of the connecting rods may be adjusted tochange the level of protrusion of the mandible. A dentist may determinea level of protrusion for the mandible that will determine the length ofthe connecting rods.

Some MRDs are structured to push the mandible forward relative to themaxilla while other MADs, such as the ResMed Narval CC™ MRD are designedto retain the mandible in a forward position. This device also reducesor minimises dental and temporo-mandibular joint (TMJ) side effects.Thus, it is configured to minimises or prevent any movement of one ormore of the teeth.

2.2.3.6 Vent Technologies

Some forms of treatment systems may include a vent to allow the washoutof exhaled carbon dioxide. The vent may allow a flow of gas from aninterior space of a patient interface, e.g., the plenum chamber, to anexterior of the patient interface, e.g., to ambient. The vent maycomprise an orifice and gas may flow through the orifice in use of themask. Many such vents are noisy. Others may become blocked in use andthus provide insufficient washout. Some vents may be disruptive of thesleep of a bed partner 1100 of the patient 1000, e.g. through noise orfocussed airflow.

ResMed Limited has developed a number of improved mask venttechnologies. See International Patent Application Publication No. WO1998/034,665; International Patent Application Publication No. WO2000/078,381; U.S. Pat. No. 6,581,594; US Patent Application PublicationNo. US 2009/0050156; US Patent Application Publication No. 2009/0044808.

Table of noise of prior masks (ISO 17510-2:2007, 10 cmH₂O pressure at1m) A-weighted A-weighted sound sound power pressure Mask level dB(A)dB(A) Year Mask name type (uncertainty) (uncertainty) (approx.) Glue-on(*) nasal 50.9 42.9 1981 ResCare nasal 31.5 23.5 1993 standard (*)ResMed nasal 29.5 21.5 1998 MirageTM (*) ResMed nasal 36 (3) 28 (3) 2000UltraMirage ™ ResMed nasal 32 (3) 24 (3) 2002 Mirage Activa ™ ResMednasal 30 (3) 22 (3) 2008 Mirage Micro ™ ResMed nasal 29 (3) 22 (3) 2008Mirage ™ SoftGel ResMed nasal 26 (3) 18 (3) 2010 Mirage ™ FX ResMednasal 37   29   2004 Mirage Swift ™ pillows (*) ResMed nasal 28 (3) 20(3) 2005 Mirage Swift ™ pillows II ResMed nasal 25 (3) 17 (3) 2008Mirage Swift ™ pillows LT ResMed AirFit nasal 21 (3) 13 (3) 2014 P10pillows

(* one specimen only, measured using test method specified in ISO 3744in CPAP mode at 10 cmH₂O)Sound pressure values of a variety of objectsare listed below

A-weighted sound Object pressure dB(A) Notes Vacuum cleaner: Nilfisk 68ISO 3744 at 1 m Walter Broadly Litter Hog: B+ distance GradeConversational speech 60 1 m distance Average home 50 Quiet library 40Quiet bedroom at night 30 Background in TV studio 20

2.2.4 Diagnosis and Monitoring Systems

Polysomnography (PSG) is a conventional system for diagnosis andmonitoring of cardio-pulmonary disorders, and typically involves expertclinical staff to apply the system. PSG typically involves the placementof 15 to 20 contact sensors on a person in order to record variousbodily signals such as electroencephalography (EEG), electrocardiography(ECG), electrooculograpy (EOG), electromyography (EMG), etc. PSG forsleep disordered breathing has involved two nights of observation of apatient in a clinic, one night of pure diagnosis and a second night oftitration of treatment parameters by a clinician. PSG is thereforeexpensive and inconvenient. In particular it is unsuitable for homesleep testing.

Clinical experts may be able to diagnose or monitor patients adequatelybased on visual observation of PSG signals. However, there arecircumstances where a clinical expert may not be available, or aclinical expert may not be affordable. Different clinical experts maydisagree on a patient's condition. In addition, a given clinical expertmay apply a different standard at different times.

3 BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devicesused in the diagnosis, amelioration, treatment, or prevention ofrespiratory disorders having one or more of improved comfort, cost,efficacy, ease of use and manufacturability.

A first aspect of the present technology relates to apparatus used inthe diagnosis, amelioration, treatment or prevention of a respiratorydisorder.

Another aspect of the present technology relates to methods used in thediagnosis, amelioration, treatment or prevention of a respiratorydisorder.

An aspect of certain forms of the present technology is to providemethods and/or apparatus that improve the compliance of patients withrespiratory therapy.

Another aspect of the present technology relates to a patient interfaceincluding a seal-forming structure including a foam material and/or afoam and textile material configured and arranged to form a seal, e.g.,compression-type seal, against the patient's face.

Another aspect of the present technology relates to a patient interfaceincluding a frame including a textile material and a seal-formingstructure provided to the frame including a foam material and/or a foamand textile material. In an example, the frame geometry imparts apredetermined three-dimensional shape to the seal-forming structure.

Another aspect of the present technology relates to a full-face patientinterface including a nasal seal including a foam and textile materialand a mouth seal including a foam material.

Another aspect of the present technology relates to a patient interfaceincluding a frame including a textile material and a seal-formingstructure provided to the frame. The seal-forming structure includes afoam material and/or a foam and textile material configured and arrangedto form a seal with the patient's nose and/or mouth.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to the patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout the patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing. The patientinterface includes a frame made from a textile material, the framehaving a predetermined three-dimensional shape that is maintainedthroughout the patient's respiratory cycle, and a seal-forming structureprovided to the frame. The seal-forming structure includes a foammaterial and/or a foam and textile material configured and arranged toform a seal with the patient's nose and mouth below the patient's nasalbridge. The frame is more rigid than the seal-forming structure tosupport the seal-forming structure in use.

An aspect of one form of the present technology is a method ofmanufacturing apparatus.

An aspect of certain forms of the present technology is a medical devicethat is easy to use, e.g. by a person who does not have medicaltraining, by a person who has limited dexterity, vision or by a personwith limited experience in using this type of medical device.

Of course, portions of the aspects may form sub-aspects of the presenttechnology. Also, various ones of the sub-aspects and/or aspects may becombined in various manners and also constitute additional aspects orsub-aspects of the present technology.

Other features of the technology will be apparent from consideration ofthe information contained in the following detailed description,abstract, drawings and claims.

4 BRIEF DESCRIPTION OF THE DRAWINGS

The present technology is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings, in whichlike reference numerals refer to similar elements including:

4.1 Treatment Systems

FIG. 1A shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a nasal pillows, receiving a supply ofair at positive pressure from an RPT device 4000. Air from the RPTdevice 4000 is humidified in a humidifier 5000, and passes along an aircircuit 4170 to the patient 1000. A bed partner 1100 is also shown.

FIG. 1B shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a nasal mask, receiving a supply of airat positive pressure from an RPT device 4000. Air from the RPT device ishumidified in a humidifier 5000, and passes along an air circuit 4170 tothe patient 1000.

FIG. 1C shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a full-face mask, receiving a supply ofair at positive pressure from an RPT device 4000. Air from the RPTdevice is humidified in a humidifier 5000, and passes along an aircircuit 4170 to the patient 1000.

4.2 Respiratory System and Facial Anatomy

FIG. 2A shows an overview of a human respiratory system including thenasal and oral cavities, the larynx, vocal folds, oesophagus, trachea,bronchus, lung, alveolar sacs, heart and diaphragm.

FIG. 2B shows a view of a human upper airway including the nasal cavity,nasal bone, lateral nasal cartilage, greater alar cartilage, nostril,lip superior, lip inferior, larynx, hard palate, soft palate,oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

FIG. 2C is a front view of a face with several features of surfaceanatomy identified including the lip superior, upper vermilion, lowervermilion, lip inferior, mouth width, endocanthion, a nasal ala,nasolabial sulcus and cheilion. Also indicated are the directionssuperior, inferior, radially inward and radially outward.

FIG. 2D is a side view of a head with several features of surfaceanatomy identified including glabella, sellion, pronasale, subnasale,lip superior, lip inferior, supramenton, nasal ridge, alar crest point,otobasion superior and otobasion inferior. Also indicated are thedirections superior & inferior, and anterior & posterior.

FIG. 2E is a further side view of a head. The approximate locations ofthe Frankfort horizontal and nasolabial angle are indicated. The coronalplane is also indicated.

FIG. 2F shows a base view of a nose with several features identifiedincluding naso-labial sulcus, lip inferior, upper Vermilion, naris,subnasale, columella, pronasale, the major axis of a naris and thesagittal plane.

FIG. 2G shows a side view of the superficial features of a nose.

FIG. 2H shows subcutaneal structures of the nose, including lateralcartilage, septum cartilage, greater alar cartilage, lesser alarcartilage, sesamoid cartilage, nasal bone, epidermis, adipose tissue,frontal process of the maxilla and fibrofatty tissue.

FIG. 2I shows a medial dissection of a nose, approximately severalmillimeters from a sagittal plane, amongst other things showing theseptum cartilage and medial crus of greater alar cartilage.

FIG. 2J shows a front view of the bones of a skull including thefrontal, nasal and zygomatic bones. Nasal concha are indicated, as arethe maxilla, and mandible.

FIG. 2K shows a lateral view of a skull with the outline of the surfaceof a head, as well as several muscles. The following bones are shown:frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal,temporal and occipital. The mental protuberance is indicated. Thefollowing muscles are shown: digastricus, masseter, sternocleidomastoidand trapezius.

FIG. 2L shows an anterolateral view of a nose.

4.3 Patient Interface

FIG. 3A shows a patient interface in the form of a nasal mask inaccordance with one form of the present technology.

FIG. 3B shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3C.

FIG. 3C shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3B.

FIG. 3D shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a value of zero.

FIG. 3E shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3F.

FIG. 3F shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3E.

FIG. 3G shows a cushion for a mask that includes two pillows. Anexterior surface of the cushion is indicated. An edge of the surface isindicated. Dome and saddle regions are indicated.

FIG. 3H shows a cushion for a mask. An exterior surface of the cushionis indicated. An edge of the surface is indicated. A path on the surfacebetween points A and B is indicated. A straight line distance between Aand B is indicated. Two saddle regions and a dome region are indicated.

FIG. 3I shows the surface of a structure, with a one dimensional hole inthe surface. Plane curve 301D forms the boundary of a one dimensionalhole.

FIG. 3J shows a cross-section through the structure of FIG. 3I. Surface302D that bounds a two dimensional hole in the structure of FIG. 3I isindicated.

FIG. 3K shows a perspective view of the structure of FIG. 3I, includingthe two dimensional hole and the one dimensional hole. Surface 302D thatbounds a two dimensional hole in the structure of FIG. 3I is indicated.

FIG. 3L shows a mask having an inflatable bladder as a cushion.

FIG. 3M shows a cross-section through the mask of FIG. 3L, and shows theinside surface of the bladder.

FIG. 3N illustrates a left-hand rule.

FIG. 3O illustrates a right-hand rule.

FIG. 3P shows a left ear, including a left ear helix.

FIG. 3Q shows a right ear, including a right ear helix.

FIG. 3R shows a right-hand helix.

FIG. 3S shows a view of a mask, including the sign of the torsion of thespace curve defined by the edge of the sealing membrane in differentregions of the mask.

FIG. 4 is a perspective view of a patient interface shown on a patient'shead according to an example of the present technology.

FIG. 5 is another perspective view of the patient interface of FIG. 4shown on a patient's head according to an example of the presenttechnology.

FIG. 6 is another perspective view of the patient interface of FIG. 4shown on a patient's head according to an example of the presenttechnology.

FIG. 7 is another perspective view of the patient interface of FIG. 4shown on a patient's head according to an example of the presenttechnology.

FIG. 8 is a side view of the patient interface of FIG. 4 shown on apatient's head according to an example of the present technology.

FIG. 9 is a perspective view of the patient interface of FIG. 4according to an example of the present technology, the patient interfaceshown with the headgear removed.

FIG. 10 is a bottom view of the patient interface of FIG. 9 according toan example of the present technology.

FIG. 11 is a rear view of the patient interface of FIG. 9 according toan example of the present technology.

FIG. 12 is another rear view of the patient interface of FIG. 9according to an example of the present technology.

FIG. 13 is another rear view of the patient interface of FIG. 9according to an example of the present technology.

FIG. 14 shows a fabric material for a frame according to an example ofthe present technology.

FIG. 15 shows the fabric material of FIG. 14 folded into athree-dimensional shape of a frame according to an example of thepresent technology.

FIG. 16 shows the fabric material of FIG. 15 joined to hold athree-dimensional shape of a frame according to an example of thepresent technology.

FIG. 17 shows the fabric material of FIG. 16 once joined to produce aninternal, three-dimensional shape of a frame according to an example ofthe present technology.

FIG. 18 shows the fabric, three-dimensional frame of FIG. 17 in positionon a patient's face according to an example of the present technology.

FIG. 19 is another view showing the fabric, three-dimensional frame ofFIG. 17 in position on a patient's face according to an example of thepresent technology.

FIG. 20A is a perspective view of a patient interface shown on apatient's head according to another example of the present technology.

FIG. 20B is a perspective view of a patient interface shown on apatient's head according to another example of the present technology.

FIG. 20C is a perspective view of a patient interface shown on apatient's head according to another example of the present technology.

5 DETAILED DESCRIPTION OF EXAMPLES OF THE TECHNOLOGY

Before the present technology is described in further detail, it is tobe understood that the technology is not limited to the particularexamples described herein, which may vary. It is also to be understoodthat the terminology used in this disclosure is for the purpose ofdescribing only the particular examples discussed herein, and is notintended to be limiting.

The following description is provided in relation to various exampleswhich may share one or more common characteristics and/or features. Itis to be understood that one or more features of any one example may becombinable with one or more features of another example or otherexamples. In addition, any single feature or combination of features inany of the examples may constitute a further example.

5.1 Therapy

In one form, the present technology comprises a method for treating arespiratory disorder comprising the step of applying positive pressureto the entrance of the airways of a patient 1000.

In certain examples of the present technology, a supply of air atpositive pressure is provided to the nasal passages of the patient viaone or both nares.

In certain examples of the present technology, mouth breathing islimited, restricted or prevented.

5.2 Treatment Systems

In one form, the present technology comprises an apparatus or device fortreating a respiratory disorder. The apparatus or device may comprise anRPT device 4000 for supplying pressurised air to the patient 1000 via anair circuit 4170 to a patient interface 3000, e.g., see FIGS. 1A to 1C.

5.3 Patient Interface

A non-invasive patient interface 3000 in accordance with one aspect ofthe present technology comprises the following functional aspects: aseal-forming structure 3100, a plenum chamber 3200, a positioning andstabilising structure 3300, a vent 3400, one form of connection port3600 for connection to air circuit 4170, and a forehead support 3700. Insome forms a functional aspect may be provided by one or more physicalcomponents. In some forms, one physical component may provide one ormore functional aspects. In use the seal-forming structure 3100 isarranged to surround an entrance to the airways of the patient so as tofacilitate the supply of air at positive pressure to the airways.

FIGS. 4 to 13 show a non-invasive patient interface 6000 in accordancewith one aspect of the present technology comprising a frame 6100 (alsoreferred to as a fascia), a seal-forming structure 6200, an air deliverytube 6600, and a positioning and stabilising structure (e.g., headgear6800). FIGS. 4 to 8 are exemplary views of the patient interface 6000 ona patient's head, and FIGS. 9 to 13 are exemplary views of the patientinterface 6000 with the headgear 6800 removed.

In use, one form of the seal-forming structure 6200 is arranged tosurround an entrance to the airways of the patient 1000 so as tofacilitate the supply of air at positive pressure to the airways. Theseal-forming structure 6200 may also be commonly referred to as acushion. In some forms, a functional aspect may be provided by one ormore physical components. In some forms, one physical component mayprovide one or more functional aspects.

In the illustrated example, the seal-forming structure 6200 includes afoam material and/or a foam and textile material configured and arrangedto form a seal, e.g., compression-type seal, against the patient's face.That is, the seal-forming structure 6200 provides a foam interfaceand/or a foam and textile interface in which a surface of the foamand/or textile is adapted to contact or engage the patient's face tocreate the seal against the patient's face, e.g., compression of thefoam and/or textile (e.g., via tightening of the headgear) creates theseal.

The frame or fascia 6100 is constructed of a more rigid material thanthe seal-forming structure 6200 and provides an interface with the airdelivery tube 6600 and the headgear 6800. In an example, the frame ismore rigid than the seal-forming structure to support the seal-formingstructure in use. In the illustrated example, the frame 6100 includes atextile material that is connected or otherwise provided to theseal-forming structure 6200. The frame 6100 may be permanently orremovably connected to the seal-forming structure 6200. The frame 6100and the seal-forming structure 6200 cooperate to form the plenum chamberor breathing chamber 6500.

In the illustrated example, the patient interface is anoro-nasal/full-face interface type including a seal-forming structure6200 structured to form a seal around the patient's nose and mouth belowthe patient's nasal bridge. As illustrated, the patient interface isprovided without a forehead support. However, aspects of the presenttechnology may be adapted for use with other suitable interface types,e.g., nasal interface.

For example, FIGS. 20A, 20B, and 20C show alternative examples ofpatient interfaces. As illustrated, the patient interfaces 7000, 8000,9000 include a frame and seal-forming structure including a foam and/ora textile material. In these examples, at least a portion of theheadgear may include a textile material that may be integrated orotherwise provide an interface with the frame/seal-forming structure.

5.3.1 Seal-Forming Structure

The upper portion of the seal-forming structure 6200 includes a nasalcushion 6300 (also referred to as a nasal seal or cradle seal)structured to seal around the lower portion of the patient's nose, e.g.,around the ala and tip of the nose, and the lower portion of theseal-forming structure 6200 includes a mouth or cushion 6400 (alsoreferred to as a mouth seal) structured to seal around the patient'smouth, e.g., at least along the sides of the mouth and along the lowerlip/chin region. The nasal cushion 6300 and the mouth cushion 6400cooperate to define, at least in part, the plenum chamber 6500.

In an example, the periphery of the seal provided by the nasal cushion6300 and the mouth cushion 6400 (e.g., see FIG. 13) travels around themouth from the left lower nose corner to the right lower nose corner viathe chin cleft. From the left and right lower nose corners, the sealdeviates sharply (e.g., nearly 90 degrees) to seal around the outeredges of underside of the patient's nose.

In an example, the patient interface 6000 may be referred to as a“compact” patient interface or mask as the patient interface provides acompact form adapted to seal along a lower portion of the patient'snose, i.e., below the nasal bridge region of the patient's nose.

Nasal Cushion

As illustrated, the nasal cushion 6300 is provided or otherwiseconnected to an upper portion of the mouth cushion 6400 such that thenasal cushion 6300 extends along the upper part of a perimeter of theplenum chamber 6500 and the nasal cushion extends along the sides andlower part of the perimeter of the plenum chamber 6500.

In the illustrated example, the nasal cushion 6300 includes a foamcomponent 6305, e.g., formed by die cutting, including two separateopenings therethrough. In an example, the thickness of the foamcomponent is constant, e.g., 10-15 mm, e.g., 12 mm. However, thicker andthinner foam may be used and the thickness of the foam may not beuniform, e.g., thickness may vary in one or more regions of the nasalcushion. In an alternative example, the foam component of the nasalcushion may be compression cut, e.g., to provide more rounded andtapered edges and/or openings, structured to more closely followcontours of the patient's nose.

To enhance the robustness and seal of the nasal cushion 6300, anairtight or impermeable textile membrane 6310 (e.g., elastic clothmembrane) is provided to the top surface or face contacting side of thefoam component 6305. In the illustrated example, the outer perimeter ofthe membrane 6310 is joined to the foam component 6305 which allows themembrane 6310 to inflate and displace relative to the foam component6305 during therapy. As illustrated, the membrane 6310 includes twoseparate openings 6315 that substantially align with the openings in thefoam component 6305. The openings 6315 are unattached or free in orderto allow treatment pressure to enter between the foam component 6305 andthe membrane 6310, which allows the inflation of the membrane 6310 inuse. In an alternative example, the foam component and/or the membranemay include a single opening.

In an example, one or both sides of the membrane 6310 (i.e., facecontacting side and/or non-face contacting side) is laminated, sealed,or provided with an impermeable surface (e.g., impermeable siliconelayer) in order to provide an air-tight or impermeable structure adaptedto inflate during therapy. For example, the non-face contacting side ofthe membrane 6310 may be laminated. Such arrangement provides a fabricpressure activated seal structured to inflate and minimise or preventleaks with complex anthropometric regions of the patient's nose, e.g.,concave and convex profiles of the patient's nose. That is, the textilemembrane or textile material of the nasal cushion is structured toinflate and displace relative to the foam component or textile materialof the nasal cushion during therapy in order to provide a pressureactivated seal against the patient's face in an area proximal thepatient's nose.

In an example, the membrane 6310 and foam component 6305 may functionsimilar to a dual wall cushion made of silicone. For example, in oneform, the membrane 6310 is structured to inflate and sealing engageagainst the underside and sides of the patient's nose during therapy,e.g., seal around both nares. This arrangement allows the nose to remainsealed with the nasal cushion 6300 even when the nose is displaced orspaced from the foam component 6305. For example, the inflation enablesthe nasal seal provided by the nasal cushion 6300 to behave dynamicallysuch that any movements of the nose away from the face contacting sideof the foam component 6305 can seal via the combination of the membrane6310 and the treatment pressure causing the membrane 6310 to dynamicallyinflate. The seal may remain dynamic only within a certain range ofmovement as the membrane 6310 may only inflate to a certain extent.

In the illustrated example, the membrane 6310 may only be provided tothe top surface or face contacting side of the foam component 6305, suchthat exposed foam from the foam component 6305 is provided along thesides of the foam component 6305. Such arrangement provides foamsurfaces at the corners of the patient's nose to help attain seal inthese regions.

The nasal cushion 6300 includes a bridge portion 6330 that extends orbridges across the upper portion of the mouth cushion 6400. The bridgeportion 6330 is not required to form a seal as it is located entirelywithin the sealing periphery of the seal-forming structure 6200. In anexample, the bridge portion 6330 may provide one or more of thefollowing features: extra sealing surface to facilitate seal at thecorners of the nose; seamless integration between the mouth andundernose sealing surfaces; support against the patient's face; and/orsemantics for setup.

As best shown in FIG. 13, the nasal cushion 6300 includes a V-shape(e.g., generally concave in shape) configured and arranged to capture orcradle the patient's nose and seal along the alar angle of the patient'snose. In an example, the nasal cushion 6300 may be shaped such that thenasal cushion 6300 will compress at different rates under the nose toachieve seal and comfort.

Mouth Cushion

The mouth cushion 6400 provides a seal that extends around the mouthfrom the left lower nose corner to the right lower nose corner via thechin cleft, and then blends seamlessly into the nasal cushion 6300.

In the illustrated example, the mouth cushion 6400 includes a foamcomponent 6405, e.g., formed by die cutting. In an example, thethickness of the foam component is constant, e.g., 10-15 mm, e.g., 12mm. However, thicker and thinner foam may be used and the thickness ofthe foam may not be uniform, e.g., thickness may vary in one or moreregions of the mouth cushion. In an alternative example, the foamcomponent of the mouth cushion may be compression cut, e.g., to providemore rounded and tapered edges, structured to more closely followcontours of the patient's face.

In the illustrated example, the mouth cushion 6400 may vary in widtharound its perimeter to enhance sealing and comfort around the patient'smouth.

Alternative Aspects

In one form of the present technology, the seal-forming structureprovides a seal-forming surface, and may additionally provide acushioning function.

In an alternative example, one or more portions of the seal-formingstructure in accordance with the present technology may be constructedfrom a soft, flexible, resilient material such as silicone.

In one form, the seal-forming structure may comprise a sealing flangeand a support flange. The sealing flange comprises a relatively thinmember with a thickness of less than about 1mm, for example about 0.25mm to about 0.45 mm, that extends around the perimeter of the plenumchamber. Support flange may be relatively thicker than the sealingflange. The support flange is disposed between the sealing flange andthe marginal edge of the plenum chamber, and extends at least part ofthe way around the perimeter. The support flange is or includes aspring-like element and functions to support the sealing flange frombuckling in use. In use the sealing flange can readily respond to systempressure in the plenum chamber acting on its underside to urge it intotight sealing engagement with the face.

In one form the seal-forming portion of the non-invasive patientinterface may comprise a pair of nasal puffs, or nasal pillows, eachnasal puff or nasal pillow being constructed and arranged to form a sealwith a respective naris of the nose of a patient.

Nasal pillows in accordance with an aspect of the present technologyinclude: a frusto-cone, at least a portion of which forms a seal on anunderside of the patient's nose, a stalk, a flexible region on theunderside of the frusto-cone and connecting the frusto-cone to thestalk. In addition, the structure to which the nasal pillow of thepresent technology is connected includes a flexible region adjacent thebase of the stalk. The flexible regions can act in concert to facilitatea universal joint structure that is accommodating of relative movementboth displacement and angular of the frusto-cone and the structure towhich the nasal pillow is connected. For example, the frusto-cone may beaxially displaced towards the structure to which the stalk is connected.

In one form, the non-invasive patient interface comprises a seal-formingportion that forms a seal in use on an upper lip region (that is, thelip superior) of the patient's face.

In one form the non-invasive patient interface comprises a seal-formingportion that forms a seal in use on a chin-region of the patient's face.

In certain forms of the present technology, a seal-forming structure isconfigured to correspond to a particular size of head and/or shape offace. For example one form of a seal-forming structure is suitable for alarge sized head, but not a small sized head. In another example, a formof seal-forming structure is suitable for a small sized head, but not alarge sized head.

5.3.2 Frame

The three-dimensional shape of the seal-forming structure 6200 aroundthe patient's nose and mouth is provided by the support of the morerigid textile frame 6100. That is, the textile frame 6100 includes apredetermined three-dimensional structure, shape, or geometry whichprovides plenum chamber 6500 and edges or surfaces configured andarranged to support and shape the seal-forming structure 6200 into apre-formed three-dimensional shape adapted to closely follow and sealalong the contours of the patient's nose and mouth. In an example, thepredetermined three-dimensional shape of the frame 6100 is maintainedthroughout the patient's respiratory cycle.

That is, edges of the frame 6100 provide cushion support surfacesstructured and arranged to support and hold the nasal cushion 6300 andthe mouth cushion 6400 in predetermined shapes to closely match contoursof the patient's nose and mouth, i.e., frame geometry imparts apredetermined three-dimensional shape to the nasal and mouth cushions6300, 6400 when the nasal and mouth cushions are attached to the cushionsupport surfaces of the frame 6100 so as to adjust the shape of thenasal and mouth cushions to match a curvature of the patient's nose andmouth. In an example, the cushion support surfaces may include differentcurvatures in different regions along its perimeter to impart differentshapes or curvatures in different regions of the nasal and mouthcushions.

As best shown in FIGS. 7 and 10 (i.e., views from the top and bottom ofthe patient interface), the frame 6100 has concave, exterior surfaceswhich are configured to closely follow or match the contour of anadjacent seal-forming structure when compressed. This arrangement helpsimprove the stability of the patient interface as it does not need toovercome external geometries trying to unseat the patient interface fromthe patient's face.

In the illustrated example, frame 6100 is constructed or made of anairtight or impermeable textile material. In an example, one or bothsides of the textile material (i.e., internal and/or external surfacesof the frame) is coated, laminated, sealed, or provided with animpermeable surface (e.g., impermeable silicone layer or membraneimbedded in textile material) in order to provide an air-tight orimpermeable structure. Such arrangement provides an impermeablestructure for the plenum chamber 6500.

In an example, the frame 6100 is formed by cutting a flat piece oftextile material into a particular geometry so that when bent/folded andjoined creates a 3-dimensional shape. Alternatively, the frame may beformed by thermoforming textile material into the desired 3-dimensionalshape to suit the patient's face. Other methods of fabric shaping mayalso be applicable. In another alternative, the frame 6100 may include aspacer fabric having a three-dimensional knitted fabric structure.

In an example, an internal structural skeleton frame may be added to thetextile frame to provide further support for the nasal and/or mouthcushion, e.g., create a surface for the nasal cushion to rest against.In an example, the skeleton frame may be permanently attached on theinside of the textile frame. For a thermoformed textile frame, allinternal structural support may be incorporated into the thermoformingprocess. In an example, the textile material of the frame includes astructure of a textile scaffold, mesh, netting or webbing.

FIGS. 14 to 19 provide exemplary steps for forming the three-dimensionalshape of the textile frame 6100 according to an example of the presenttechnology. For example, FIG. 14 shows a textile or fabric material 6105(with an impermeable surface) that is cut or otherwise formed into apredetermined flat shape that provides the necessary material toconstruct the three-dimensional frame 6100. FIG. 15 shows the fabricmaterial 6105 of FIG. 14 folded in a particular manner into thethree-dimensional shape of the frame 6100. FIG. 16 shows the folded,fabric material 6105 of FIG. 15 joined at the front edge 6110 and theshort sides 6115 of the chin fold to hold the three-dimensional shape ofthe frame 6100. As shown in FIG. 9 for example, the front joint 6110acts as a central spine for the frame 6100. FIG. 17 shows the joined,fabric material 6105 of FIG. 16 which produces an internal,three-dimensional shape of the plenum chamber 6500 provided by the frame6100. FIGS. 18 and 19 shows the fabric, three-dimensional frame 6100 ofFIG. 17 in position on a patient's face, which shows the frameconforming to the sides and lower portion of the mouth.

The nasal cushion 6300 is provided to an upper portion of the frame 6100to form the upper part of the patient interface, and mouth cushion 6400is provided to the frame 6100 and joined with the nasal cushion 6300 tocomplete the seal-forming structure 6200. The air delivery tube 6600(e.g., straight tube) is positioned to protrude from the bottom of theframe 6100. In an example, the air delivery tube may include a swivel atone or both ends.

5.3.3 Plenum Chamber

In an example, the plenum chamber 6500 has a perimeter that is shaped tobe complementary to the surface contour of the face of an average personin the region where a seal will form in use. In use, a marginal edge ofthe plenum chamber 6500 is positioned in close proximity to an adjacentsurface of the face. Actual contact with the face is provided by theseal-forming structure 6200. The seal-forming structure 6200 may extendin use about the entire perimeter of the plenum chamber 6500.

5.3.4 Positioning and Stabilising Structure

The seal-forming structure 6200 of the patient interface 6000 of thepresent technology may be held in sealing position in use by theheadgear 6800.

As illustrated in FIGS. 4 to 8, the headgear 6800 includes a pair ofupper side straps 6802 and a pair of lower side straps 6804 connected toa circular crown strap 6806 that encapsulates the crown of the patient'shead. As best shown in FIGS. 6, 7, and 9, the upper side straps 6802connect to respective upper headgear connectors 6130 of the frame 6100and the lower side straps 6804 connect to respective lower headgearconnectors 6150 of the frame 6100, e.g., via respective headgear clips6160, 6161. The side straps 6802, 6804 may include an adjustable hookand loop (Velcro™) connection mechanism, e.g., Velcro™-like hook tabs,to facilitate connection and/or adjustment.

The upper and lower headgear connectors 6130, 6150 provide a 4-pointconnection to the headgear 6800. As best shown in FIG. 8, each of theupper side straps 6802 is arranged to extend between the patient's earand eye and provide an upper force vector that extends upwardly at anangle with respect to the Frankfort horizontal line. Each of the lowerside straps 6804 is arranged to extend below the patient's ear andprovide a lower force vector that extends generally parallel to theFrankfort horizontal line. Such arrangement ensures that suitable forcevectors are provided to seal the seal-forming structure 6200 with boththe patient's nose and mouth.

The two upper force vectors strategically pass directly over the cornersof the nose in order to maximise foam compression in this region for arobust seal. The two upper vectors are attached to the front portion ofthe frame, which enables the rear of the upper portion of the frame(where the foam seal is attached) to splay out and conform to thepatient's face shape, e.g., conform to region incorporating seal at thecorner of the nose.

The two lower force vectors are positioned towards the rear of the framedirectly above the foam seal. This enables the headgear to directlyapply force onto the foam seal. This is the widest part of the patientinterface which correlates to the largest force pulling the patientinterface away from the patient's face.

In this way, the upper force vectors will draw the nasal cushion 6300 upand into sealing engagement with the patient's nose and the lower forcevectors will draw the mouth cushion 6400 back and into sealingengagement around the patient's mouth. Thus, the resultant force vectorwhen headgear tension is applied allows for effective sealing at boththe nasal cushion 6300 and the mouth cushion 6400.

In the illustrated example, each of the upper and lower headgearconnectors 6130, 6150 of the frame 6100 includes a headgear connectionpoint in the form of a magnetic connector 6155 (e.g., encased magnet)structured to locate and connect to a magnet 6162 associated with therespective headgear clip 6160, 6161 provided to a respective strap ofthe headgear 6800, e.g., see FIGS. 4, 5, 6, 7, and 9. However, it shouldbe appreciated that the upper and lower headgear connectors 6130, 6150may be connected with headgear straps of the headgear in other suitablemanners.

In one form of the present technology, a positioning and stabilisingstructure is provided that is configured in a manner consistent withbeing worn by a patient while sleeping. In one example the positioningand stabilising structure has a low profile, or cross-sectionalthickness, to reduce the perceived or actual bulk of the apparatus. Inone example, the positioning and stabilising structure comprises atleast one strap having a rectangular cross-section. In one example thepositioning and stabilising structure comprises at least one flat strap.

In one form of the present technology, a positioning and stabilisingstructure comprises a strap constructed from a laminate of a fabricpatient-contacting layer, a foam inner layer and a fabric outer layer.In one form, the foam is porous to allow moisture, (e.g., sweat), topass through the strap. In one form, the fabric outer layer comprisesloop material to engage with a hook material portion.

In certain forms of the present technology, a positioning andstabilising structure comprises a strap that is extensible, e.g.resiliently extensible. For example the strap may be configured in useto be in tension, and to direct a force to draw a cushion into sealingcontact with a portion of a patient's face. In an example the strap maybe configured as a tie.

In certain forms of the present technology, a positioning andstabilising structure comprises a strap that is bendable and e.g.non-rigid. An advantage of this aspect is that the strap is morecomfortable for a patient to lie upon while the patient is sleeping.

In certain forms of the present technology, a positioning andstabilizing structure provides a retaining force configured tocorrespond to a particular size of head and/or shape of face. Forexample one form of positioning and stabilizing structure provides aretaining force suitable for a large sized head, but not a small sizedhead. In another example, a form of positioning and stabilizingstructure provides a retaining force suitable for a small sized head,but not a large sized head.

5.3.5 Vent

In one form, the patient interface 6000 includes a vent 6900 constructedand arranged to allow for the washout of exhaled gases, e.g. carbondioxide.

One form of vent 6900 in accordance with the present technologycomprises a plurality of holes, for example, about 20 to about 80 holes,or about 40 to about 60 holes, or about 45 to about 55 holes.

The vent 6900 may be located in the plenum chamber 6500, e.g., providedto the frame 6100. Alternatively, the vent 6900 is located in adecoupling structure, e.g., a swivel.

5.3.6 Decoupling Structure(s)

In one form the patient interface includes at least one decouplingstructure, for example, a swivel or a ball and socket.

5.3.7 Connection Port

In an example, the patient interface includes a connection port thatallows for connection to the air circuit 4170.

5.3.8 Forehead Support

In one form, the patient interface includes a forehead support.

5.3.9 Anti-Asphyxia Valve

In one form, the patient interface includes an anti-asphyxia valve.

5.3.10 Ports

In one form of the present technology, a patient interface includes oneor more ports that allow access to the volume within the plenum chamber.In one form this allows a clinician to supply supplemental oxygen. Inone form, this allows for the direct measurement of a property of gaseswithin the plenum chamber, such as the pressure.

5.4 Glossary

For the purposes of the present technology disclosure, in certain formsof the present technology, one or more of the following definitions mayapply. In other forms of the present technology, alternative definitionsmay apply.

5.4.1 General

Air: In certain forms of the present technology, air may be taken tomean atmospheric air, and in other forms of the present technology airmay be taken to mean some other combination of breathable gases, e.g.atmospheric air enriched with oxygen.

Ambient: In certain forms of the present technology, the term ambientwill be taken to mean (i) external of the treatment system or patient,and (ii) immediately surrounding the treatment system or patient.

For example, ambient humidity with respect to a humidifier may be thehumidity of air immediately surrounding the humidifier, e.g. thehumidity in the room where a patient is sleeping. Such ambient humiditymay be different to the humidity outside the room where a patient issleeping.

In another example, ambient pressure may be the pressure immediatelysurrounding or external to the body.

In certain forms, ambient (e.g., acoustic) noise may be considered to bethe background noise level in the room where a patient is located, otherthan for example, noise generated by an RPT device or emanating from amask or patient interface. Ambient noise may be generated by sourcesoutside the room.

Automatic Positive Airway Pressure (APAP) therapy: CPAP therapy in whichthe treatment pressure is automatically adjustable, e.g. from breath tobreath, between minimum and maximum limits, depending on the presence orabsence of indications of SDB events.

Continuous Positive Airway Pressure (CPAP) therapy: Respiratory pressuretherapy in which the treatment pressure is approximately constantthrough a respiratory cycle of a patient. In some forms, the pressure atthe entrance to the airways will be slightly higher during exhalation,and slightly lower during inhalation. In some forms, the pressure willvary between different respiratory cycles of the patient, for example,being increased in response to detection of indications of partial upperairway obstruction, and decreased in the absence of indications ofpartial upper airway obstruction.

Flow rate: The volume (or mass) of air delivered per unit time. Flowrate may refer to an instantaneous quantity. In some cases, a referenceto flow rate will be a reference to a scalar quantity, namely a quantityhaving magnitude only. In other cases, a reference to flow rate will bea reference to a vector quantity, namely a quantity having bothmagnitude and direction. Flow rate may be given the symbol Q. ‘Flowrate’ is sometimes shortened to simply ‘flow’.

In the example of patient respiration, a flow rate may be nominallypositive for the inspiratory portion of a breathing cycle of a patient,and hence negative for the expiratory portion of the breathing cycle ofa patient. Total flow rate, Qt, is the flow rate of air leaving the RPTdevice. Vent flow rate, Qv, is the flow rate of air leaving a vent toallow washout of exhaled gases. Leak flow rate, Ql, is the flow rate ofleak from a patient interface system or elsewhere. Respiratory flowrate, Qr, is the flow rate of air that is received into the patient'srespiratory system.

Leak: The word leak will be taken to be an unintended flow of air. Inone example, leak may occur as the result of an incomplete seal betweena mask and a patient's face. In another example leak may occur in aswivel elbow to the ambient.

Noise, conducted (acoustic): Conducted noise in the present documentrefers to noise which is carried to the patient by the pneumatic path,such as the air circuit and the patient interface as well as the airtherein. In one form, conducted noise may be quantified by measuringsound pressure levels at the end of an air circuit.

Noise, radiated (acoustic): Radiated noise in the present documentrefers to noise which is carried to the patient by the ambient air. Inone form, radiated noise may be quantified by measuring soundpower/pressure levels of the object in question according to ISO 3744.

Noise, vent (acoustic): Vent noise in the present document refers tonoise which is generated by the flow of air through any vents such asvent holes of the patient interface.

Patient: A person, whether or not they are suffering from a respiratorydisease.

Pressure: Force per unit area. Pressure may be expressed in a range ofunits, including cmH₂O, g-f/cm² and hectopascal. 1 cmH₂O is equal to 1g-f/cm² and is approximately 0.98 hectopascal. In this specification,unless otherwise stated, pressure is given in units of cmH₂O.

The pressure in the patient interface is given the symbol Pm, while thetreatment pressure, which represents a target value to be achieved bythe mask pressure Pm at the current instant of time, is given the symbolPt.

Respiratory Pressure Therapy (RPT): The application of a supply of airto an entrance to the airways at a treatment pressure that is typicallypositive with respect to atmosphere.

Ventilator: A mechanical device that provides pressure support to apatient to perform some or all of the work of breathing.

5.4.1.1 Materials

Silicone or Silicone Elastomer: A synthetic rubber. In thisspecification, a reference to silicone is a reference to liquid siliconerubber (LSR) or a compression moulded silicone rubber (CMSR). One formof commercially available LSR is SILASTIC (included in the range ofproducts sold under this trademark), manufactured by Dow Corning.Another manufacturer of LSR is Wacker. Unless otherwise specified to thecontrary, an exemplary form of LSR has a Shore A (or Type A) indentationhardness in the range of about 35 to about 45 as measured using ASTMD2240.

Polycarbonate: a typically transparent thermoplastic polymer ofBisphenol-A Carbonate.

5.4.1.2 Mechanical Properties

Resilience: Ability of a material to absorb energy when deformedelastically and to release the energy upon unloading.

-   ‘Resilient’: Will release substantially all of the energy when    unloaded. Includes e.g. certain silicones, and thermoplastic    elastomers.

Hardness: The ability of a material per se to resist deformation (e.g.described by a Young's Modulus, or an indentation hardness scalemeasured on a standardised sample size).

-   ‘Soft’ materials may include silicone or thermo-plastic elastomer    (TPE), and may, e.g. readily deform under finger pressure.-   ‘Hard’ materials may include polycarbonate, polypropylene, steel or    aluminium, and may not e.g. readily deform under finger pressure.

Stiffness (or rigidity) of a structure or component: The ability of thestructure or component to resist deformation in response to an appliedload. The load may be a force or a moment, e.g. compression, tension,bending or torsion. The structure or component may offer differentresistances in different directions.

-   ‘Floppy’ structure or component: A structure or component that will    change shape, e.g. bend, when caused to support its own weight,    within a relatively short period of time such as 1 second.-   ‘Rigid’ structure or component: A structure or component that will    not substantially change shape when subject to the loads typically    encountered in use. An example of such a use may be setting up and    maintaining a patient interface in sealing relationship with an    entrance to a patient's airways, e.g. at a load of approximately 20    to 30 cmH₂O pressure.

As an example, an I-beam may comprise a different bending stiffness(resistance to a bending load) in a first direction in comparison to asecond, orthogonal direction. In another example, a structure orcomponent may be floppy in a first direction and rigid in a seconddirection.

5.4.2 Respiratory Cycle

Apnea: According to some definitions, an apnea is said to have occurredwhen flow falls below a predetermined threshold for a duration, e.g. 10seconds. An obstructive apnea will be said to have occurred when,despite patient effort, some obstruction of the airway does not allowair to flow. A central apnea will be said to have occurred when an apneais detected that is due to a reduction in breathing effort, or theabsence of breathing effort, despite the airway being patent. A mixedapnea occurs when a reduction or absence of breathing effort coincideswith an obstructed airway.

Breathing rate: The rate of spontaneous respiration of a patient,usually measured in breaths per minute.

Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.

Effort (breathing): The work done by a spontaneously breathing personattempting to breathe.

Expiratory portion of a breathing cycle: The period from the start ofexpiratory flow to the start of inspiratory flow.

Flow limitation: Flow limitation will be taken to be the state ofaffairs in a patient's respiration where an increase in effort by thepatient does not give rise to a corresponding increase in flow. Whereflow limitation occurs during an inspiratory portion of the breathingcycle it may be described as inspiratory flow limitation. Where flowlimitation occurs during an expiratory portion of the breathing cycle itmay be described as expiratory flow limitation.

Types of flow limited inspiratory waveforms:

(i) Flattened: Having a rise followed by a relatively flat portion,followed by a fall.

(ii) M-shaped: Having two local peaks, one at the leading edge, and oneat the trailing edge, and a relatively flat portion between the twopeaks.

(iii) Chair-shaped: Having a single local peak, the peak being at theleading edge, followed by a relatively flat portion.

(iv) Reverse-chair shaped: Having a relatively flat portion followed bysingle local peak, the peak being at the trailing edge.

Hypopnea: According to some definitions, a hypopnea is taken to be areduction in flow, but not a cessation of flow. In one form, a hypopneamay be said to have occurred when there is a reduction in flow below athreshold rate for a duration. A central hypopnea will be said to haveoccurred when a hypopnea is detected that is due to a reduction inbreathing effort. In one form in adults, either of the following may beregarded as being hypopneas:

-   (i) a 30% reduction in patient breathing for at least 10 seconds    plus an associated 4% desaturation; or-   (ii) a reduction in patient breathing (but less than 50%) for at    least 10 seconds, with an associated desaturation of at least 3% or    an arousal.

Hyperpnea: An increase in flow to a level higher than normal.

Inspiratory portion of a breathing cycle: The period from the start ofinspiratory flow to the start of expiratory flow will be taken to be theinspiratory portion of a breathing cycle.

Patency (airway): The degree of the airway being open, or the extent towhich the airway is open. A patent airway is open. Airway patency may bequantified, for example with a value of one (1) being patent, and avalue of zero (0), being closed (obstructed).

Positive End-Expiratory Pressure (PEEP): The pressure above atmospherein the lungs that exists at the end of expiration.

Peak flow rate (Qpeak): The maximum value of flow rate during theinspiratory portion of the respiratory flow waveform.

Respiratory flow rate, patient airflow rate, respiratory airflow rate(Qr): These terms may be understood to refer to the RPT device'sestimate of respiratory airflow rate, as opposed to “true respiratoryflow rate” or “true respiratory airflow rate”, which is the actualrespiratory flow rate experienced by the patient, usually expressed inlitres per minute.

Tidal volume (Vt): The volume of air inhaled or exhaled during normalbreathing, when extra effort is not applied.

(inhalation) Time (Ti): The duration of the inspiratory portion of therespiratory flow rate waveform.

(exhalation) Time (Te): The duration of the expiratory portion of therespiratory flow rate waveform.

(total) Time (Ttot): The total duration between the start of oneinspiratory portion of a respiratory flow rate waveform and the start ofthe following inspiratory portion of the respiratory flow rate waveform.

Typical recent ventilation: The value of ventilation around which recentvalues of ventilation Vent over some predetermined timescale tend tocluster, that is, a measure of the central tendency of the recent valuesof ventilation.

Upper airway obstruction (UAO): includes both partial and total upperairway obstruction. This may be associated with a state of flowlimitation, in which the flow rate increases only slightly or may evendecrease as the pressure difference across the upper airway increases(Starling resistor behaviour).

Ventilation (Vent): A measure of a rate of gas being exchanged by thepatient's respiratory system. Measures of ventilation may include one orboth of inspiratory and expiratory flow, per unit time. When expressedas a volume per minute, this quantity is often referred to as “minuteventilation”. Minute ventilation is sometimes given simply as a volume,understood to be the volume per minute.

5.4.3 Ventilation

Adaptive Servo-Ventilator (ASV): A servo-ventilator that has achangeable, rather than fixed target ventilation. The changeable targetventilation may be learned from some characteristic of the patient, forexample, a respiratory characteristic of the patient.

Backup rate: A parameter of a ventilator that establishes the minimumbreathing rate (typically in number of breaths per minute) that theventilator will deliver to the patient, if not triggered by spontaneousrespiratory effort.

Cycled: The termination of a ventilator's inspiratory phase. When aventilator delivers a breath to a spontaneously breathing patient, atthe end of the inspiratory portion of the breathing cycle, theventilator is said to be cycled to stop delivering the breath.

Expiratory positive airway pressure (EPAP): a base pressure, to which apressure varying within the breath is added to produce the desired maskpressure which the ventilator will attempt to achieve at a given time.

End expiratory pressure (EEP): Desired mask pressure which theventilator will attempt to achieve at the end of the expiratory portionof the breath. If the pressure waveform template Π(Φ) is zero-valued atthe end of expiration, i.e. Π(Φ)=0 when Φ=1, the EEP is equal to theEPAP.

Inspiratory positive airway pressure (IPAP): Maximum desired maskpressure which the ventilator will attempt to achieve during theinspiratory portion of the breath.

Pressure support: A number that is indicative of the increase inpressure during ventilator inspiration over that during ventilatorexpiration, and generally means the difference in pressure between themaximum value during inspiration and the base pressure (e.g.,PS=IPAP−EPAP). In some contexts pressure support means the differencewhich the ventilator aims to achieve, rather than what it actuallyachieves.

Servo-ventilator: A ventilator that measures patient ventilation, has atarget ventilation, and which adjusts the level of pressure support tobring the patient ventilation towards the target ventilation.

Spontaneous/Timed (S/T): A mode of a ventilator or other device thatattempts to detect the initiation of a breath of a spontaneouslybreathing patient. If however, the device is unable to detect a breathwithin a predetermined period of time, the device will automaticallyinitiate delivery of the breath.

Swing: Equivalent term to pressure support.

Triggered: When a ventilator delivers a breath of air to a spontaneouslybreathing patient, it is said to be triggered to do so at the initiationof the respiratory portion of the breathing cycle by the patient'sefforts.

Typical recent ventilation: The typical recent ventilation Vtyp is thevalue around which recent measures of ventilation over somepredetermined timescale tend to cluster. For example, a measure of thecentral tendency of the measures of ventilation over recent history maybe a suitable value of a typical recent ventilation.

5.4.4 Anatomy 5.4.4.1 Anatomy of the Face

Ala: the external outer wall or “wing” of each nostril (plural: alar)

Alare: The most lateral point on the nasal ala.

Alar curvature (or alar crest) point: The most posterior point in thecurved base line of each ala, found in the crease formed by the union ofthe ala with the cheek.

Auricle: The whole external visible part of the ear.

(nose) Bony framework: The bony framework of the nose comprises thenasal bones, the frontal process of the maxillae and the nasal part ofthe frontal bone.

(nose) Cartilaginous framework: The cartilaginous framework of the nosecomprises the septal, lateral, major and minor cartilages.

Columella: the strip of skin that separates the nares and which runsfrom the pronasale to the upper lip.

Columella angle: The angle between the line drawn through the midpointof the nostril aperture and a line drawn perpendicular to the Frankfurthorizontal while intersecting subnasale.

Frankfort horizontal plane: A line extending from the most inferiorpoint of the orbital margin to the left tragion. The tragion is thedeepest point in the notch superior to the tragus of the auricle.

Glabella: Located on the soft tissue, the most prominent point in themidsagittal plane of the forehead.

Lateral nasal cartilage: A generally triangular plate of cartilage. Itssuperior margin is attached to the nasal bone and frontal process of themaxilla, and its inferior margin is connected to the greater alarcartilage.

Lip, lower (labrale inferius):

Lip, upper (labrale superius):

Greater alar cartilage: A plate of cartilage lying below the lateralnasal cartilage. It is curved around the anterior part of the naris. Itsposterior end is connected to the frontal process of the maxilla by atough fibrous membrane containing three or four minor cartilages of theala.

Nares (Nostrils): Approximately ellipsoidal apertures forming theentrance to the nasal cavity. The singular form of nares is naris(nostril). The nares are separated by the nasal septum.

Naso-labial sulcus or Naso-labial fold: The skin fold or groove thatruns from each side of the nose to the corners of the mouth, separatingthe cheeks from the upper lip.

Naso-labial angle: The angle between the columella and the upper lip,while intersecting subnasale.

Otobasion inferior: The lowest point of attachment of the auricle to theskin of the face.

Otobasion superior: The highest point of attachment of the auricle tothe skin of the face.

Pronasale: the most protruded point or tip of the nose, which can beidentified in lateral view of the rest of the portion of the head.

Philtrum: the midline groove that runs from lower border of the nasalseptum to the top of the lip in the upper lip region.

Pogonion: Located on the soft tissue, the most anterior midpoint of thechin.

Ridge (nasal): The nasal ridge is the midline prominence of the nose,extending from the Sellion to the Pronasale.

Sagittal plane: A vertical plane that passes from anterior (front) toposterior (rear) dividing the body into right and left halves.

Sellion: Located on the soft tissue, the most concave point overlyingthe area of the frontonasal suture.

Septal cartilage (nasal): The nasal septal cartilage forms part of theseptum and divides the front part of the nasal cavity.

Subalare: The point at the lower margin of the alar base, where the alarbase joins with the skin of the superior (upper) lip.

Subnasal point: Located on the soft tissue, the point at which thecolumella merges with the upper lip in the midsagittal plane.

Supramentale: The point of greatest concavity in the midline of thelower lip between labrale inferius and soft tissue pogonion

5.4.4.2 Anatomy of the Skull

Frontal bone: The frontal bone includes a large vertical portion, thesquama frontalis, corresponding to the region known as the forehead.

Mandible: The mandible forms the lower jaw. The mental protuberance isthe bony protuberance of the jaw that forms the chin.

Maxilla: The maxilla forms the upper jaw and is located above themandible and below the orbits. The frontal process of the maxillaprojects upwards by the side of the nose, and forms part of its lateralboundary.

Nasal bones: The nasal bones are two small oblong bones, varying in sizeand form in different individuals; they are placed side by side at themiddle and upper part of the face, and form, by their junction, the“bridge” of the nose.

Nasion: The intersection of the frontal bone and the two nasal bones, adepressed area directly between the eyes and superior to the bridge ofthe nose.

Occipital bone: The occipital bone is situated at the back and lowerpart of the cranium. It includes an oval aperture, the foramen magnum,through which the cranial cavity communicates with the vertebral canal.The curved plate behind the foramen magnum is the squama occipitalis.

Orbit: The bony cavity in the skull to contain the eyeball.

Parietal bones: The parietal bones are the bones that, when joinedtogether, form the roof and sides of the cranium.

Temporal bones: The temporal bones are situated on the bases and sidesof the skull, and support that part of the face known as the temple.

Zygomatic bones: The face includes two zygomatic bones, located in theupper and lateral parts of the face and forming the prominence of thecheek.

5.4.4.3 Anatomy of the Respiratory System

Diaphragm: A sheet of muscle that extends across the bottom of the ribcage. The diaphragm separates the thoracic cavity, containing the heart,lungs and ribs, from the abdominal cavity. As the diaphragm contractsthe volume of the thoracic cavity increases and air is drawn into thelungs.

Larynx: The larynx, or voice box houses the vocal folds and connects theinferior part of the pharynx (hypopharynx) with the trachea.

Lungs: The organs of respiration in humans. The conducting zone of thelungs contains the trachea, the bronchi, the bronchioles, and theterminal bronchioles. The respiratory zone contains the respiratorybronchioles, the alveolar ducts, and the alveoli.

Nasal cavity: The nasal cavity (or nasal fossa) is a large air filledspace above and behind the nose in the middle of the face. The nasalcavity is divided in two by a vertical fin called the nasal septum. Onthe sides of the nasal cavity are three horizontal outgrowths callednasal conchae (singular “concha”) or turbinates. To the front of thenasal cavity is the nose, while the back blends, via the choanae, intothe nasopharynx.

Pharynx: The part of the throat situated immediately inferior to (below)the nasal cavity, and superior to the oesophagus and larynx. The pharynxis conventionally divided into three sections: the nasopharynx(epipharynx) (the nasal part of the pharynx), the oropharynx(mesopharynx) (the oral part of the pharynx), and the laryngopharynx(hypopharynx).

5.4.5 Patient Interface

Anti-asphyxia valve (AAV): The component or sub-assembly of a masksystem that, by opening to atmosphere in a failsafe manner, reduces therisk of excessive CO₂ rebreathing by a patient.

Elbow: An elbow is an example of a structure that directs an axis offlow of air travelling therethrough to change direction through anangle. In one form, the angle may be approximately 90 degrees. Inanother form, the angle may be more, or less than 90 degrees. The elbowmay have an approximately circular cross-section. In another form theelbow may have an oval or a rectangular cross-section. In certain formsan elbow may be rotatable with respect to a mating component, e.g. about360 degrees. In certain forms an elbow may be removable from a matingcomponent, e.g. via a snap connection. In certain forms, an elbow may beassembled to a mating component via a one-time snap during manufacture,but not removable by a patient.

Frame: Frame will be taken to mean a mask structure that bears the loadof tension between two or more points of connection with a headgear. Amask frame may be a non-airtight load bearing structure in the mask.However, some forms of mask frame may also be air-tight.

Headgear: Headgear will be taken to mean a form of positioning andstabilizing structure designed for use on a head. For example theheadgear may comprise a collection of one or more struts, ties andstiffeners configured to locate and retain a patient interface inposition on a patient's face for delivery of respiratory therapy. Someties are formed of a soft, flexible, elastic material such as alaminated composite of foam and fabric.

Membrane: Membrane will be taken to mean a typically thin element thathas, preferably, substantially no resistance to bending, but hasresistance to being stretched.

Plenum chamber: a mask plenum chamber will be taken to mean a portion ofa patient interface having walls at least partially enclosing a volumeof space, the volume having air therein pressurised above atmosphericpressure in use. A shell may form part of the walls of a mask plenumchamber.

Seal: May be a noun form (“a seal”) which refers to a structure, or averb form (“to seal”) which refers to the effect. Two elements may beconstructed and/or arranged to ‘seal’ or to effect ‘sealing’therebetween without requiring a separate ‘seal’ element per se.

Shell: A shell will be taken to mean a curved, relatively thin structurehaving bending, tensile and compressive stiffness. For example, a curvedstructural wall of a mask may be a shell. In some forms, a shell may befaceted. In some forms a shell may be airtight. In some forms a shellmay not be airtight.

Stiffener: A stiffener will be taken to mean a structural componentdesigned to increase the bending resistance of another component in atleast one direction.

Strut: A strut will be taken to be a structural component designed toincrease the compression resistance of another component in at least onedirection.

Swivel (noun): A subassembly of components configured to rotate about acommon axis, preferably independently, preferably under low torque. Inone form, the swivel may be constructed to rotate through an angle of atleast 360 degrees. In another form, the swivel may be constructed torotate through an angle less than 360 degrees. When used in the contextof an air delivery conduit, the sub-assembly of components preferablycomprises a matched pair of cylindrical conduits. There may be little orno leak flow of air from the swivel in use.

Tie (noun): A structure designed to resist tension.

Vent: (noun): A structure that allows a flow of air from an interior ofthe mask, or conduit, to ambient air for clinically effective washout ofexhaled gases. For example, a clinically effective washout may involve aflow rate of about 10 litres per minute to about 100 litres per minute,depending on the mask design and treatment pressure.

5.4.6 Shape of Structures

Products in accordance with the present technology may comprise one ormore three-dimensional mechanical structures, for example a mask cushionor an impeller. The three-dimensional structures may be bounded bytwo-dimensional surfaces. These surfaces may be distinguished using alabel to describe an associated surface orientation, location, function,or some other characteristic. For example a structure may comprise oneor more of an anterior surface, a posterior surface, an interior surfaceand an exterior surface. In another example, a cushion structure maycomprise a face-contacting (e.g. outer) surface, and a separatenon-face-contacting (e.g. underside or inner) surface. In anotherexample, a structure may comprise a first surface and a second surface.

To facilitate describing the shape of the three-dimensional structuresand the surfaces, we first consider a cross-section through a surface ofthe structure at a point, p. See FIG. 3B to FIG. 3F, which illustrateexamples of cross-sections at point p on a surface, and the resultingplane curves. FIGS. 3B to 3F also illustrate an outward normal vector atp. The outward normal vector at p points away from the surface. In someexamples we describe the surface from the point of view of an imaginarysmall person standing upright on the surface.

5.4.6.1 Curvature in One Dimension

The curvature of a plane curve at p may be described as having a sign(e.g. positive, negative) and a magnitude (e.g. 1/radius of a circlethat just touches the curve at p).

Positive curvature: If the curve at p turns towards the outward normal,the curvature at that point will be taken to be positive (if theimaginary small person leaves the point p they must walk uphill). SeeFIG. 3B (relatively large positive curvature compared to FIG. 3C) andFIG. 3C (relatively small positive curvature compared to FIG. 3B). Suchcurves are often referred to as concave.

Zero curvature: If the curve at p is a straight line, the curvature willbe taken to be zero (if the imaginary small person leaves the point p,they can walk on a level, neither up nor down). See FIG. 3D.

Negative curvature: If the curve at p turns away from the outwardnormal, the curvature in that direction at that point will be taken tobe negative (if the imaginary small person leaves the point p they mustwalk downhill). See FIG. 3E (relatively small negative curvaturecompared to FIG. 3F) and FIG. 3F (relatively large negative curvaturecompared to FIG. 3E). Such curves are often referred to as convex.

5.4.6.2 Curvature of Two Dimensional Surfaces

A description of the shape at a given point on a two-dimensional surfacein accordance with the present technology may include multiple normalcross-sections. The multiple cross-sections may cut the surface in aplane that includes the outward normal (a “normal plane”), and eachcross-section may be taken in a different direction. Each cross-sectionresults in a plane curve with a corresponding curvature. The differentcurvatures at that point may have the same sign, or a different sign.Each of the curvatures at that point has a magnitude, e.g. relativelysmall. The plane curves in FIGS. 3B to 3F could be examples of suchmultiple cross-sections at a particular point.

Principal curvatures and directions: The directions of the normal planeswhere the curvature of the curve takes its maximum and minimum valuesare called the principal directions. In the examples of FIG. 3B to FIG.3F, the maximum curvature occurs in FIG. 3B, and the minimum occurs inFIG. 3F, hence FIG. 3B and FIG. 3F are cross sections in the principaldirections. The principal curvatures at p are the curvatures in theprincipal directions.

Region of a surface: A connected set of points on a surface. The set ofpoints in a region may have similar characteristics, e.g. curvatures orsigns.

Saddle region: A region where at each point, the principal curvatureshave opposite signs, that is, one is positive, and the other is negative(depending on the direction to which the imaginary person turns, theymay walk uphill or downhill).

Dome region: A region where at each point the principal curvatures havethe same sign, e.g. both positive (a “concave dome”) or both negative (a“convex dome”).

Cylindrical region: A region where one principal curvature is zero (or,for example, zero within manufacturing tolerances) and the otherprincipal curvature is non-zero.

Planar region: A region of a surface where both of the principalcurvatures are zero (or, for example, zero within manufacturingtolerances).

Edge of a surface: A boundary or limit of a surface or region.

Path: In certain forms of the present technology, ‘path’ will be takento mean a path in the mathematical—topological sense, e.g. a continuousspace curve from f(0) to f(1) on a surface. In certain forms of thepresent technology, a ‘path’ may be described as a route or course,including e.g. a set of points on a surface. (The path for the imaginaryperson is where they walk on the surface, and is analogous to a gardenpath).

Path length: In certain forms of the present technology, ‘path length’will be taken to the distance along the surface from f(0) to f(1), thatis, the distance along the path on the surface. There may be more thanone path between two points on a surface and such paths may havedifferent path lengths. (The path length for the imaginary person wouldbe the distance they have to walk on the surface along the path).

Straight-line distance: The straight-line distance is the distancebetween two points on a surface, but without regard to the surface. Onplanar regions, there would be a path on the surface having the samepath length as the straight-line distance between two points on thesurface. On non-planar surfaces, there may be no paths having the samepath length as the straight-line distance between two points. (For theimaginary person, the straight-line distance would correspond to thedistance ‘as the crow flies’.)

5.4.6.3 Space Curves

Space curves: Unlike a plane curve, a space curve does not necessarilylie in any particular plane. A space curve may be considered to be aone-dimensional piece of three-dimensional space. An imaginary personwalking on a strand of the DNA helix walks along a space curve. Atypical human left ear comprises a left-hand helix, see FIG. 3P. Atypical human right ear comprises a right-hand helix, see FIG. 3Q. FIG.3R shows a right-hand helix. The edge of a structure, e.g. the edge of amembrane or impeller, may follow a space curve. In general, a spacecurve may be described by a curvature and a torsion at each point on thespace curve. Torsion is a measure of how the curve turns out of a plane.Torsion has a sign and a magnitude. The torsion at a point on a spacecurve may be characterised with reference to the tangent, normal andbinormal vectors at that point.

Tangent unit vector (or unit tangent vector): For each point on a curve,a vector at the point specifies a direction from that point, as well asa magnitude. A tangent unit vector is a unit vector pointing in the samedirection as the curve at that point. If an imaginary person were flyingalong the curve and fell off her vehicle at a particular point, thedirection of the tangent vector is the direction she would betravelling.

Unit normal vector: As the imaginary person moves along the curve, thistangent vector itself changes. The unit vector pointing in the samedirection that the tangent vector is changing is called the unitprincipal normal vector. It is perpendicular to the tangent vector.

Binormal unit vector: The binormal unit vector is perpendicular to boththe tangent vector and the principal normal vector. Its direction may bedetermined by a right-hand rule (see e.g. FIG. 3O), or alternatively bya left-hand rule (FIG. 3N).

Osculating plane: The plane containing the unit tangent vector and theunit principal normal vector. See FIGS. 3N and 3O.

Torsion of a space curve: The torsion at a point of a space curve is themagnitude of the rate of change of the binormal unit vector at thatpoint. It measures how much the curve deviates from the osculatingplane. A space curve which lies in a plane has zero torsion. A spacecurve which deviates a relatively small amount from the osculating planewill have a relatively small magnitude of torsion (e.g. a gently slopinghelical path). A space curve which deviates a relatively large amountfrom the osculating plane will have a relatively large magnitude oftorsion (e.g. a steeply sloping helical path). With reference to FIG.3R, since T2>T1, the magnitude of the torsion near the top coils of thehelix of FIG. 3R is greater than the magnitude of the torsion of thebottom coils of the helix of FIG. 3R

With reference to the right-hand rule of FIG. 3O, a space curve turningtowards the direction of the right-hand binormal may be considered ashaving a right-hand positive torsion (e.g. a right-hand helix as shownin FIG. 3R). A space curve turning away from the direction of theright-hand binormal may be considered as having a right-hand negativetorsion (e.g. a left-hand helix).

Equivalently, and with reference to a left-hand rule (see FIG. 3N), aspace curve turning towards the direction of the left-hand binormal maybe considered as having a left-hand positive torsion (e.g. a left-handhelix). Hence left-hand positive is equivalent to right-hand negative.See FIG. 3S.

5.4.6.4 Holes

A surface may have a one-dimensional hole, e.g. a hole bounded by aplane curve or by a space curve. Thin structures (e.g. a membrane) witha hole, may be described as having a one-dimensional hole. See forexample the one dimensional hole in the surface of structure shown inFIG. 3I, bounded by the plane curve 301D.

A structure may have a two-dimensional hole, e.g. a hole bounded by asurface. For example, an inflatable tyre has a two dimensional holebounded by the inside surface of the tyre. In another example, a bladderwith a cavity for air or gel could have a two-dimensional hole. See forexample the cushion of FIG. 3L and the example cross-section therethrough in FIG. 3M. In a yet another example, a conduit may comprise aone-dimension hole (e.g. at its entrance or at its exit), and atwo-dimension hole bounded by the inside surface of the conduit. Seealso the two dimensional hole through the structure shown in FIG. 3K,bounded by surface 302D.

5.5 Other Remarks

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in Patent Office patent files orrecords, but otherwise reserves all copyright rights whatsoever.

Unless the context clearly dictates otherwise and where a range ofvalues is provided, it is understood that each intervening value, to thetenth of the unit of the lower limit, between the upper and lower limitof that range, and any other stated or intervening value in that statedrange is encompassed within the technology. The upper and lower limitsof these intervening ranges, which may be independently included in theintervening ranges, are also encompassed within the technology, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the technology.

Furthermore, where a value or values are stated herein as beingimplemented as part of the technology, it is understood that such valuesmay be approximated, unless otherwise stated, and such values may beutilized to any suitable significant digit to the extent that apractical technical implementation may permit or require it.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this technology belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present technology, a limitednumber of the exemplary methods and materials are described herein.

When a particular material is identified as being used to construct acomponent, obvious alternative materials with similar properties may beused as a substitute. Furthermore, unless specified to the contrary, anyand all components herein described are understood to be capable ofbeing manufactured and, as such, may be manufactured together orseparately.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include their plural equivalents,unless the context clearly dictates otherwise.

All publications mentioned herein are incorporated herein by referencein their entirety to disclose and describe the methods and/or materialswhich are the subject of those publications. The publications discussedherein are provided solely for their disclosure prior to the filing dateof the present application. Nothing herein is to be construed as anadmission that the present technology is not entitled to antedate suchpublication by virtue of prior invention. Further, the dates ofpublication provided may be different from the actual publication dates,which may need to be independently confirmed.

The terms “comprises” and “comprising” should be interpreted asreferring to elements, components, or steps in a non-exclusive manner,indicating that the referenced elements, components, or steps may bepresent, or utilized, or combined with other elements, components, orsteps that are not expressly referenced.

The subject headings used in the detailed description are included onlyfor the ease of reference of the reader and should not be used to limitthe subject matter found throughout the disclosure or the claims. Thesubject headings should not be used in construing the scope of theclaims or the claim limitations.

Although the technology herein has been described with reference toparticular examples, it is to be understood that these examples aremerely illustrative of the principles and applications of thetechnology. In some instances, the terminology and symbols may implyspecific details that are not required to practice the technology. Forexample, although the terms “first” and “second” may be used, unlessotherwise specified, they are not intended to indicate any order but maybe utilised to distinguish between distinct elements. Furthermore,although process steps in the methodologies may be described orillustrated in an order, such an ordering is not required. Those skilledin the art will recognize that such ordering may be modified and/oraspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be madeto the illustrative examples and that other arrangements may be devisedwithout departing from the spirit and scope of the technology.

5.6 REFERENCE SIGNS LIST Number Feature Item 1000 patient 1100 bedpartner 3000 patient interface 3100 seal - forming structure 3200 plenumchamber 3300 positioning and stabilising structure 3400 vent 3600connection port 3700 forehead support 4000 RPT device 4170 air circuit5000 humidifier 6000 patient interface 6100 frame 6105 fabric material6110 front j oint 6115 side 6130 upper headgear connector 6150 lowerheadgear connector 6155 magnetic connector 6160 headgear clip 6161headgear clip 6162 magnet 6200 seal - forming structure 6300 nasalcushion 6305 foam component 6310 membrane 6315 opening 6330 bridgeportion 6400 mouth cushion 6405 foam component 6500 plenum chamber 6600air delivery tube 6800 headgear 6802 upper side strap 6804 lower sidestrap 6806 crown strap 6900 vent 7000 patient interface 8000 patientinterface 9000 patient interface

1. A patient interface for sealed delivery of a flow of air at acontinuously positive pressure with respect to ambient air pressure toan entrance to the patient's airways including at least entrance of apatient's nares, wherein the patient interface is configured to maintaina therapy pressure in a range of about 4 cmH₂O to about 30 cmH₂O aboveambient air pressure in use, throughout the patient's respiratory cycle,while the patient is sleeping, to ameliorate sleep disordered breathing;said patient interface comprising: a seal-forming structure configuredand arranged to form a seal against a patient's face, whereinseal-forming structure includes a foam material and a textile material,the textile material comprising a seal-forming surface configured andarranged to sealingly engage the patient's face, wherein the foammaterial includes a patient facing surface configured and arranged toface the patient in use, wherein an outer perimeter of the textilematerial is joined to the patient facing surface of the foam material,wherein at least a portion of the textile material is unattached to thepatient facing surface of the foam material to allow the flow of air atthe therapy pressure to enter between the textile material and thepatient facing surface of the foam material during therapy, which allowsthe textile material to inflate and displace relative to the patientfacing surface of the foam material during therapy in order to provide apressure activated seal against the patient's face.
 2. The patientinterface according to claim 1, further comprising a frame made from atextile material, wherein the seal-forming structure is provided to theframe, and wherein the frame has a predetermined three-dimensional shapethat is maintained throughout the patient's respiratory cycle.
 3. Thepatient interface according to claim 1, wherein the seal-formingstructure includes a nasal cushion configured and arranged to form aseal around a lower portion of the patient's nose below the patient'snasal bridge.
 4. The patient interface according to claim 3, wherein thenasal cushion is structured to seal around the ala and tip of thepatient's nose.
 5. The patient interface according to claim 3, whereinthe nasal cushion comprises said foam material and said textilematerial.
 6. The patient interface according to claim 5, wherein thetextile material of the nasal cushion includes two separate openings andthe foam material of the nasal cushion includes two separate openings,and the two separate openings of the textile material of the nasalcushion substantially aligns with the two separate openings of the foammaterial of the nasal cushion.
 7. The patient interface according toclaim 5, wherein the foam material of the nasal cushion comprises abridge portion.
 8. The patient interface according to claim 7, whereinthe bridge portion does not form a seal with the patient's face, in use.9. The patient interface according to claim 5, wherein the seal-formingstructure further includes a mouth cushion configured and arranged toform a seal around at least a portion of the patient's mouth at leastalong the sides of the mouth and along the lower lip/chin region. 10.The patient interface according to claim 9, wherein the mouth cushioncomprises a foam material.
 11. The patient interface according to claim10, wherein the mouth cushion further comprises a textile material. 12.The patient interface according to claim 10, wherein the textilematerial of the nasal cushion forms at least one opening to deliver theflow of air to the patient's nares, and the foam material of the mouthcushion forms an opening to deliver the flow of air to the patient'smouth, and the at least one opening of the textile material of the nasalcushion is separate and distinct from the opening of the foam materialof the mouth cushion.
 13. The patient interface according to claim 9,wherein the mouth cushion is structured to seal around the mouth fromthe left lower nose corner to the right lower nose corner via the chincleft.
 14. The patient interface according to claim 1, wherein at leastone side of the textile material includes an air impermeable surfacewhich allows the textile material to inflate and displace relative tothe foam material of the nasal cushion during therapy.
 15. The patientinterface according to claim 14, wherein the air impermeable surfacecomprises a silicone layer.
 16. The patient interface according to claim14, wherein the air impermeable surface is on a non patient contactingside of the textile material.
 17. The patient interface according toclaim 1, wherein inflation and displacement of the textile materialrelative to the foam material during therapy allows sealing even whenthe patient's face is displaced or spaced from the foam material. 18.The patient interface according to claim 1, further comprising apositioning and stabilising structure to hold the seal-forming structurein sealing position in use, at least a portion of the positioning andstabilising structure including a textile material.
 19. The patientinterface according to claim 18, wherein the textile material of thepositioning and stabilising structure is integrated or provides aninterface with the seal-forming structure and/or a frame that supportsthe seal-forming structure.
 20. The patient interface according to claim1, further comprising a frame structured to impart a predeterminedthree-dimensional shape to the seal-forming structure.